Benign prostatic hyperplasia (BPH) is the most common proliferative disease of the prostate in men in the United States. More than two thirds of men over age 50 have some degree of BPH. Treatment for BPH approaches $5 billion annually. Prostate enlargement may lead to urinary retention and, in some cases, renal impairment. The NIDDK has sponsored a large clinical trial entitled "Medical Therapy of Prostate Symptoms (MTOPS)" that tested the ability of two medications, the 5 a-reductase inhibitor finasteride and the alpha-1 adrenergic receptor blocker doxazosin, alone or in combination, to treat this disorder. As part of this study, over 3000 men had annual serum samples drawn and approximately 1000 men had prostate biopsies at 0, 1 and 5 years of the study. These now comprise a large archival collection of clinical specimens currently being housed at our institution. The availability of these specimens presents a valuable opportunity for research to identify genetic and biologic markers that will further our understanding of the causes and progression of prostatic diseases and responses to therapy. The overall aim of this application is to establish a Pathology Coordinating Center (PCC) in support of the MTOPS Prostate Samples Analysis (MPSA) Consortium as described in RFA-DK-02-017. In response to the RFA, the Pathology Coordinating Center will provide expertise and resources in the areas of: 1) Archival Repository Management and Distribution, acting as a repository for all the serum and tissue specimens generated by the MTOPS project; 2) Histopathology, including diagnostic interpretation, paraffin processing and microtomy, cryomicrotomy, conventional light microscopy, laser capture microdissection, tissue arrays, immunohistochemistry, and imaging; and 3) Specialized Sample Preparation including high-quality DNA purifications, protein extractions for protein arrays and other proteomic applications, and SMARTa cDNA amplification of RNA. Our intent is to provide the highest quality non-biased patient samples prepared to meet the needs of individual research teams whether their studies focus on genetics, gene expression, or proteomics. It is our belief that the quality, reliability and applicability of biomarker research in prostatic diseases can only be guaranteed through the use of high quality non-biased patient specimens that have been handled, processed and interpreted in a uniform manner that can be directly linked to clinical information and outcome.